• Boby Lessard

    Project Title: To Be Added

  • Briana Cabral

    Project Title: Participatory Stakeholder co-design and the Pilot Phase of the Opal Mobile Phone Application .

  • Ian Benlolo

    Project Title: To be Added

  • Jordan Bourgault

    Project Title: Validation par simulation Monte-Carlo GEANT4 du blindage de la voûte d’un cyclotron utilisé pour la production de 18F .

  • Peter Kim

    Project Title: To Be Added .

  • Philippe Chatigny

    Project Title: To Be Added .

  • Samuel Thibodeau

    Project Title: To be Added

  • Stacey Beard

    Project Title: Online Registration System for the Multi-Institutional Expansion of the Opal Patient Portal .

  • Tristan Shoemaker

    Project Title: Dosimetric Study of Image Guided High Dose Rate Brachytherapy Treatment of Colorectal Cancer with 192Ir, 75Se and 169Yb .

  • Yujing Zou

    Project Title: A radiomics study: Comparison of lymphadenopathy prediction power between 2D and 3D features from head and neck cancer dual-energy CTs .

Boby Lessard Abstract

To Be Added.

Boby Lessard Publications

1. To Be Added.

Ian Benlolo Abstract

To be added.

Ian Benlolo Publications

1. To Be Added.

Jordan Bourgault Abstract

Afin de développer des plans de traitement efficaces et ciblés pour le cancer, il est primordial de connaître avec le plus de précision possible la localisation des cellules tumorales. La tomographie par émission de positons, couramment utilisée en clinique oncologique à fins d’imagerie, amène un coût d’opération élevé dû à la production des radio-isotopes nécessaires à son fonctionnement. Pour limiter ces dépenses, il est pertinent de produire ces radio-isotopes sur leur site d’utilisation pour limiter les pertes dues à leur courte demi-vie (~110 min pour le 18F). Par contre, la fabrication de ces isotopes nécessite un accélérateur de particules tel un cyclotron. Dans le cas du 18F, on bombarde un volume d’eau lourde (H2 18O) avec un faisceau de protons. Ces protons interagissent avec le noyau des molécules d’eau lourde, ce qui émet une grande quantité de neutrons. Ces neutrons posent un problème de radio-protection, d’où la nécessité d’un blindage autour de l’appareil. L’objectif de ce projet est de confirmer que ce blindage est suffisant.

Le logiciel de simulations d’interactions particulaires Monte-Carlo GEANT4 est utilisé pour étudier la pénétration des neutrons dans les murs de béton de la voûte. Simuler l’interaction entre les protons et l’eau lourde est une opération de calcul très coûteuse. De ce fait,le programme de simulations se base sur les spectres énergétiques fournis par les manufacturiers de cyclotrons. La géométrie de la voûte et de son entourage est basée sur les plans de la nouvelle annexe du complexe hospitalier de l’Enfant-Jésus. Plusieurs types de béton sont testés, car une certaine concentration d’éléments tel le bore limite, entre autres, la production de photons secondaires .

Jordan Bourgault Publications

1. To Be Added.

Tristan Shoemaker Abstract

Purpose: To investigate differences between prescribed and administered dose in high dose rate (HDR) endorectal brachytherapy (HDR-EBT) by evaluating dose to clinical target volume (CTV) and organs at risk (OARs) calculated with a Monte Carlo based dose calculation software, RapidBrachyMC. In addition, dose coverage, conformity and homogeneity were compared between the radionuclides 192Ir, 75Se and 169Yb for use in HDR-EBT.
Methods: Post implant dosimetry was performed using RapidBrachyMC for 8 patients, 3 fractions each, treated with HDR-EBT utilising the 192Ir MicroSelectronV2 source and a flexible intracavitary applicator fitting a tungsten rod for OARs shielding. Four tissue segmentation schemes were used; (1) according to the TG-43 formalism, (2) material and nominal densities assigned to contours of foreign objects, patient tissues as in (1), (3) tissue materials and nominal densities assigned to contoured organs in addition to foreign objects, (4) materials specified as (3) but mass densities for patient contours were derived from CT Hounsfield Units. Clinical plans optimized for 192Ir were used, however the results for 75Se and 169Yb were normalized to D90 of the clinical plan.
Results: TG-43 based dosimetry overestimates CTV coverage and dose to the OARs, pelvic and femur bone for 192Ir, while for 175Se and 69Yb dose to CTV and OARs are overestimated, but pelvic and femur bone doses are significantly underestimated. 75Se delivers similar dose to OARs as 192Ir but delivers slightly increased bone doses. 169Yb delivers lower dose to the rectum but significantly higher bone dose.
Conclusions: Ignoring high-Z material, specifically for radionuclides with lower average energy than 192Ir, contributes to significant inaccuracies leading to sub-optimal dose optimization and disagreement between prescribed and delivered dose. Our results also show that with a future MRI-based treatment planning, loss of CT-density data will not significantly affect dosimetry if material composition and nominal mass densities are used .

Tristan Shoemaker Publications

1. To Be Added.

Yujing Zou Abstract

Radiomics is the extraction and analysis of large numbers of numerical quantities (referred to as ‘features’, e.g. tumor size, gray-level co-occurrence matrix) from medical images. It is cost-effective, and it enhances the precision of disease diagnosis and prognosis. In our study, we used Dual-Energy Computed Tomography (DECT), which enables data to be acquired in 21 energy levels, ranging between 40 keV and 140 keV. Subsequently, feature values were extracted from these scans in both 2D and 3D. 2D analysis was performed on the central slice of the tumor (one slice) whereas 3D analysis was done on the entire tumor (multiple slices). 3D contouring (i.e. outlining the tumor at each slice) of CT images is significantly more time-consuming than that of 2D, and efficient cancer diagnosis is of the essence in clinic. Thus, a radiomics analysis is implemented on the DECT data to decipher if there is an energy-dependency and if 3D features outperform 2D features, both in terms of endpoint predictability for lymphadenopathy, a disease of abnormal size, number or consistency lymph nodes. Our current results suggest that extracted 2D features from DECT scans at differential energy levels may have a stronger power for predicting lymphadenopathy than that of 3D features. The superiority of 2D features over 3D features indicate that the noise introduced in 3D reduces correlation with outcome, and the noises of 3D masks may have come from the extra number of tumor slices and more tumor volume .

Yujing Zou Publications

1. To Be Added.

Samuel Thibodeau Abstract

To be added.

Samuel Thibodeau Publications

1. To Be Added.

Stacey Beard Abstract

The Opal patient portal is a mobile app which allows patients at the Cedars Cancer Centre to view their personal health information (PHI) and personalized educational material. During the summer of 2018, a partial prototype of a multi-institutional version of Opal was implemented, allowing patients to simultaneously access PHI from several hospitals at which they receive treatment. However, the prototype’s registration system has not been updated to accommodate a multi-institutional network. Additionally, the registration process is currently offline, and requires hospital employees to register patients on site and in person. This severely limits the amount of people that can be registered at once. The aim of this project is twofold: first, to migrate the existing registration system to an online platform (a module within the Opal app), and second, to adapt the registration process to function within the multi-institutional version of the app. The student will (1) study the structure of the current registration system, (2) design a multi-institutional online registration system to create an Opal account, (3) design a module enabling patients to add participating hospitals to their account, (4) implement these changes into the multi-institutional prototype, (5) merge part of the new registration system into the live app, to allow Opal to benefit from the advantages of an online system even before the multi-institutional prototype is ready for launch .

Stacey Beard Publications

1. To Be Added.

Peter Kim Abstract

To be added.

Peter Kim Publications

1. To Be Added.

Philippe Chatigny Abstract

To be added.

Philippe Chatigny Publications

1. To Be Added.

Briana Cabral Abstract

Introduction: The goal is to increase patient involvement and break down the patientclinician divide through the implementation of a patient portal called Opal. Opal was created using a participatory stakeholder co-design methodology. This design methodology ensured that all stakeholders in the final product were fully engaged in its development. Currently, Opal is in the pilot release phase, consisting of gradually increasing the number of patients using the application to access their personal health information (PHI) in
radiation oncology.

Methods: Patients and staff continue to contribute throughout the pilot stage by providing feedback that the group at Opal will use to improve subsequent Opal updates. We also trained the Cedars Cancer Foundation staff to register patients for Opal with the use of newly-developed documentation, and we observed the registration process as patients signed up. Our observations will allow us to continuously assess and improve the registration workflow.

Results: As a result of patients participating in multiple surveys, we were able to ascertain that 63.8% of patients prefer to have access to all of their PHI immediately once they are available. Of the remaining patients, 23.3% prefer to have access to all their PHI after it had been reviewed with them by their clinician, and 12.9% of patients prefer to only receive need-to-know information. From our initial experience registering patients, we have observed that all patients wish to access all of their medical data as soon as they are available. Also, the registration process will need to be fine-tuned and streamlined.

Briana Cabral Publications

1. To Be Added.